In communication networks, there is always a challenge to obtain good performance and capacity for a given communications protocol, its parameters and the physical environment in which the communication network is deployed.
Data increase in communication networks implies that the traffic load in cellular networks such as the 3rd Generation Partnership Project (3GPP) telecommunications standard and the Long Term Evolution (LTE) telecommunications standard will grow. Considering the fact that most of the data traffic occur in hot spots and buildings, the idea of using carrier grade Wi-Fi network to offload the data traffic from cellular networks has been introduced.
Since most wireless devices (in LTE termed user equipment, such as smart phones, mobile phones, tablet computers, and other handset equipment) comprise an embedded Wi-Fi module, offloading may be realized by in the wireless device setting a higher priority to Wi-Fi access. Call admission control or radio resource management methods may be used for offloading purposes. In general terms, offloading is to be interpreted as at least partly moving communications resources of a wireless device from a first network to a second network, thereby offloading the first network. These methods consider mainly radio signal strength detection/comparison and load balance when determining whether or not offloading should occur.
Wi-Fi technology has experienced a considerable evolution in the past decade: from the standards IEEE 802.11b and IEEE 802.11a to the standards IEEE 802.11g and IEEE 802.11n and recently the standard IEEE 802.11ac. Each revised version corresponds to a particular Wi-Fi physical layer (PHY) specification, i.e., to a particular hardware implementation. Even after more than 5 years of the standardization of IEEE 802.11g, many wireless devices in use only support IEEE 802.11b. Hence it is expected that there simultaneously will be wireless devices supporting communications in the 2.4 GHz frequency band (as in IEEE 802.11n, IEEE 802.11g, and IEEE 802.11b) and communications in the 5 GHz frequency band (as in IEEE 802.11n, IEEE 802.11a, and IEEE 802.11ac). Backward compatibility was therefore included from IEEE 802.11g and beyond. However, introducing a wireless device supporting a lower PHY version into a Wi-Fi network providing a higher PHY version will trigger a mixed-mode operation and lead to a performance drop of the whole Wi-Fi network.
Hence, there is still a need for an improved offloading between different types of communications networks.